Press Release

AGL, GCAL to Direct Program at Couture Providing New Research
on Targeting Affluents and Peer-to-Peer Best Practice Sharing

NEW YORK, NY ― May 25, 2007 ― American Gemological Laboratories (AGL) and Gem
Certification & Assurance Lab (GCAL), the Official Colored Gemstone and Diamond Grading
Laboratories of Couture 2007, are directing a special conference event in Las Vegas that will
allow “Couture Cornerstone Retailers” to network and explore how to better reach the elite
affluent. One of the key elements of the event is a presentation from some of the top consultants
in the luxury jewelry market from various business areas such as marketing and advertising to
interior design, in essence a “Dream Team” of some of the best industry talent. As a bonus,
conference participants will receive a free ticket for a chance to win an exclusive “Dream Team”
store makeover to be raffled off during Couture.

“This year at Couture, we have a special designation for retailers who have supported the
Couture model over the last 12 years,” said Anita O’Boyle, Group Show Director for the Nielsen
Jewelry Group, producer of Couture. “This designation as Cornerstone Retailers allows them
access to special programs like ‘Tuesday at Two,’ and the research information that will be
provided on how to capture the most elite customers. We are happy to bring these types of
programs to our event this year, and look forward to seeing the interaction and energy that is
created in this excellent session.”

The keynote speaker is Elaine Wynn, business partner and spouse of famous casino resort
developer/entrepreneur Steve Wynn, and mastermind of the spectacular Wynn retail shops of
luxury brands. Ms. Wynn will share her vision and understanding of the elite affluents’ lifestyle
and desires for memorable retail experiences.

The conference will include breakout seminars featuring specific marketing applications linked
to AGL, GCAL, and the Natural Color Diamond Association (NCDIA). Facilitators for these
sessions will be C.R. “Cap” Beesley, President of AGL; Don Palmieri, President of GCAL; and
Sam Merksamer, Executive Director of NCDIA.

Participants in “Tuesday at Two” will receive a free raffle ticket to win a “Dream Team” store
makeover , with recommendations and solutions to transform their store, business, customer
experience and brand messaging. In addition, AGL and GCAL are offering the “Dream Team”
raffle tickets to any participant at Couture show for $100 per ticket at the AGL and GCAL
“Dream Team” Lounge in the main Couture exhibit area with proceeds to benefit Jewelers For
Children (JFC). AGL and GCAL will match every $100 raffle ticket sold.

Founded by the U.S. jewelry industry in 1999, JFC has donated more than $23 million to
organizations and programs dedicated to helping children whose lives have been affected by
illness, abuse or neglect.

About American Gemological Laboratories

American Gemological Laboratories (AGL) is a subsidiary of Collectors Universe, Inc., a
NASDAQ Global Markets traded company (NASDAQ: CLCT). AGL was founded in 1977 and
has been a pioneer as the first gemological laboratory to offer colored stone grading reports and
comprehensive gemological origin reports (www.aglgemlab.com). AGL is the Official Colored
Gemstone Laboratory of the International Colored Gemstone Association for North America, the
JCK Las Vegas Show, Couture 2007, and the JA New York shows. AGL also is the Oasis
Lounge sponsor of Premiere, Prestige Promenade and Luxury by JCK.

About Gem Certification & Assurance Lab

Gem Certification & Assurance Lab (GCAL) is a subsidiary of Collectors Universe, Inc., a
NASDAQ Global Markets traded company (NASDAQ: CLCT). GCAL provides guaranteed
diamond certification with bundled services including Gemprint™ and direct light performance
analysis as well as Source Veritas™ and Ideal Cut certificates (www.gemfacts.com). GCAL is
the Official Diamond Laboratory of the International Colored Gemstone Association for North
America, the JCK Las Vegas Show, Couture 2007, and the JA New York shows. AGL also is the
Oasis Lounge sponsor of Premiere, Prestige Promenade and Luxury by JCK.